IEC 63012:2019

IEC 63012 ®
Edition 1.0 2019-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Insulating liquids – Unused modified or blended esters for electrotechnical
applications
Isolants liquides – Esters neufs modifiés ou mélangés pour applications
électrotechniques
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IEC 63012 ®
Edition 1.0 2019-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Insulating liquids – Unused modified or blended esters for electrotechnical

applications
Isolants liquides – Esters neufs modifiés ou mélangés pour applications

électrotechniques
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.040.10 ISBN 978-2-8322-6894-0

– 2 – IEC 63012:2019 © IEC 2019
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 9
4 Classification . 10
4.1 General . 10
4.2 Fire performance classification . 10
4.3 Viscosity classification . 10
5 Properties, significance and test methods . 10
5.1 Physical properties . 10
5.1.1 Appearance . 10
5.1.2 Colour . 11
5.1.3 Viscosity . 11
5.1.4 Lubricity . 11
5.1.5 Thermal conductivity . 11
5.1.6 Thermal expansion coefficient . 11
5.1.7 Specific heat capacity . 11
5.1.8 Pour point . 11
5.1.9 Water content . 12
5.1.10 Water saturation . 12
5.1.11 Density . 12
5.1.12 Interfacial tension . 12
5.2 Electrical properties . 12
5.2.1 AC breakdown voltage . 12
5.2.2 Lightning impulse breakdown voltage . 12
5.2.3 Partial discharge inception voltage (PDIV) . 13
5.2.4 Dielectric dissipation factor (DDF) . 13
5.2.5 Relative permittivity (dielectric constant) . 13
5.2.6 DC resistivity . 13
5.2.7 Electrostatic charging tendency (ECT) . 13
5.3 Chemical properties . 13
5.3.1 Acidity . 13
5.3.2 Additive content . 13
5.3.3 Corrosive and potentially corrosive sulphur compounds . 13
5.3.4 Methanol content . 14
5.4 Properties related to long term performance . 14
5.4.1 Oxidation stability . 14
5.4.2 Operating temperature . 14
5.4.3 Material compatibility . 15
5.4.4 Stray gassing . 15
5.4.5 Gassing tendency . 15
5.5 Health, safety and environmental properties . 15
5.5.1 General . 15
5.5.2 Polychlorinated biphenyls (PCBs) . 15
5.5.3 Environmental toxicity . 15

5.5.4 Flash point and fire point . 15
5.5.5 Sustainability . 16
5.5.6 Biodegradation . 16
5.5.7 Disposal . 16
6 Minimum performance requirements . 16
7 Identification and general delivery requirements . 16
Annex A (informative) Miscibility and compatibility of liquids and retrofilling of

transformers . 19
Bibliography . 20

Table 1 – Required performance characteristics of modified or blended esters . 17
Table 2 – Optional performance characteristics of modified or blended esters . 18

– 4 – IEC 63012:2019 © IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INSULATING LIQUIDS – UNUSED MODIFIED OR BLENDED ESTERS
FOR ELECTROTECHNICAL APPLICATIONS

FOREWORD
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4) In order t
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